Refrigerator evaporator



Nov. 10, 1936. L. w. ATCHISON REFRIGERATOR EVAPORATOR Filed Jan. 22, 1935 Pi .I. /4 3 Inventor-z Leonard W. At chison.

9 H S Attorheg.

Patented Nov. 10; 1936 UNITED STATES PATENT OFFICE REFRIGERATOR nvnrona'rolt Leonard W. Atchison,

signor to General Electric ration of New York Schenectady, N. Y., as- Company, a corpo- Application January 22, 1935, Serial No. 2,917

9 Claims.

tion will become apparentas the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of myv invention reference may be had to the accompanying drawing in which .Fig. 1 shows a household refrigerator provided with anevaporator embodying my invention, and Fig. 2 is an enlarged perspective view partly in section of the evaporator shown in Fig. 1. I I

Referring to the drawing, in Fig. 1 I have shown a household refrigerator comprising a cabinet I0 having a food compartment II to be cooled, and a door l2 for closing the compartment. The compartment H is cooled by an evaporator l3 arrangedin the upper portion thereof and supplied with refrigerant from a refrigerating machine comprising a closed casing M in which is arranged a motor and a compressor, a natural draft air cooled condenser l5 having a conduit I6 and a receiver or float valve chamber ll. During operation of the motor and compressor within the casing I 4 refrigerant is compressed and discharged into the conduit l6 of the condenser l5 where it is cooled and liquefied and then flows to the float valve chamber l1. When a predetermined amount of liquid refrigerant'has collected in the float valve chamber I'I, a float arranged therein rises and admits refrigerant through a conduit l8 to the evaporator It. The evaporator is arranged to cool the compartment H and also to support-freezing trays or other vessels and to freeze water desserts or the like placed therein. The liquid refrigerant is vaporized by the absorption of heat from the chamber H and from freezing trays supported on the evaporator and the vapor collects in headers l9 and 20, is withdrawn from the header 20 through a conduit 2| andreturns to the casing I 4. This cycle of operation continues as long as the motor within the casing I4 is operating. The temperature within the compartment l I may be thermostatically regulated in the usual manner by controlling the operation of the motor which drives the compressor.

In order to provide a minimum amount of obstruction within the evaporator and the refrigerator cabinet, it is desirable that the'space within the evaporator between the headers l9 and 20 be free from refrigerant conduits and the like. In accordance with my invention I provide a construction which accomplishes this purpose by arranging the two headers of the evaporator with separate groups of depending refrigerant circulating conduits, and by arranging a connection between one of the headers and the set of conduits connected to the other header so that both liquid and gaseous refrigerant collecting in the first header will be injected into the group of tubes connected to the second header.

Referring now to Fig. 2, the evaporator l3 comprises inner and outer metal sheets 22 and 23 respectively secured together face toface and bent into U-shaped form,the edges of the sheet 22 being bent around the sheet 23 as indicated at 24. The walls of the evaporator are sealed by welding them around their edges and between the passages formed therein or in any other suitable manner. The cylindrical headers l9 and 20 and the depending refrigerant passages are formed by indentations in the sheets, the headers being arranged in the upper ends of the U. The inner sheet 22 is smooth except for the header indentations therein so that the horizontal portion l3a. of the evaporator provides a suitable support for freezing trays or the like. The de-' pending refrigerant circulating passages are arranged in two groups, one group communicating with the header l9 comprising a plurality of separate U-shaped passages or tubes 25, and the other group communicating with the header 20 and comprising a plurality of separate U-shaped passages or tubes 26. Each of the U-shaped passages communicates at both ends with the same header and below the normal level of liquid refrigerant in that header.

In order to supply refrigerant to the evaporator I3, I provide a manifold 21 arranged in the bottom of the evaporator and providing communication between the liquid refrigerant supply conduit l8 and each of the U-shaped passages 25 through ducts 28. The refrigerant'fiowing from the float chamber I! through the conduit 18 enters the manifold 21 and flows through ducts 28 into the passages 25. Injection of refrigerant into the passages induces a circulation of refrigerant, which assists the natural thermally induced circulation within the passages from the header into one end of each of the U-shaped passages and then through the passages back to the header, and provides an efficient arrangement for the rapid absorption of heat by the evaporator.

This arrangement whereby the ducts introduce refrigerant into the circulating tubes in order to assist the natural thermally induced circulation regardless of the direction thereof, is not my invention, but is the invention of Delbert F. Newman, and is described and claimed in copending application, Serial No. 3,651, filed January 26, 1935, and assigned to the General Electric Company, assignee of my present invention. I do not, therefore, claim herein anything described or claimed in the said Newman application, which is to be regarded as prior art with respect to the present application, my invention relating to the arrangement of an evaporator having a plurality of headers and which does not require an equalizing connection between the headers.

Liquid refrigerant in the evaporator I3 will collect in the header I9 and normally will be approximately at a level indicated at 29, lubricant ordinarily floating on the surface of the liquid refrigerant. vaporized refrigerant will collect in the header 19 above the liquid refrigerant therein. In order to remove the vaporized refrigerant and excess liquid refrigerant and lubricant from the header I9, I provide an outlet connection 30 opening into the header l9 at the liquid level 29 therein and communicating with a manifold 3| in the bottom of the evaporator. The manifold 3| communicates with the lower ends of the U-shaped passages 26 through ducts 32, and the liquid and gaseous refrigerant received from the header I9 is injected into the passages 26 from the manifold 3| through these ducts and produces a circulation of refrigerant in the passages 26, which assists the thermally induced circulation therein as in the passages 25. The vaporized refrigerant from the header l9 and the refrigerant vaporized in the passages 26 collects in the header 20 above the level of liquid refrigerant therein and is withdrawn therefrom through the conduit 2|. Since the connection 30 and the manifold 3| convey both liquid and gaseous refrigerant with oil from the header I 9 and inject this refrigerant with oil into the passages 26, no equalizing connection is required between the headers I 9 and 20. Furthermore, as long as refrigerant is being vaporized in the header l9 and the passages 25, refrigerant vaporv will be injected into the passages 26 through the ducts 32 and will maintain a rapid circulation of liquid refrigerant in the passages 26. This rapid circulation of refrigerant provides an efficient evaporator which will rapidly absorb heat from the air in the cabinet and articles placed thereon.

During the operation of the refrigerating machine shown in Figs. 1 and 2 refrigerant is collected in the float valve chamber l1, and is admitted periodically to the evaporator l3 and, while being admitted, induces a rapid circulation of refrigerant in the U-shaped passages 25, and refrigerant is also injected into the passages '26 from the header l9 and induces a rapid circulation in the passages 26. During the idle periods of the compressor within the casing H, and during the intervals when refrigerant is not flowing from the float valve chamber l1 into the evaporator, the refrigerant evaporating within the passages 25 and the header IE will collect in this header and continue to fiow'through the connection 30 into the manifold 3| and through the ducts 32 into the passages 26 where it continues the rapid circulation of refrigerant. It will thus be seen that there is a rapid circulation of refrigerant in the passages 26 at all times when heat is being absorbed by the evaporator and is vaporizing refrigerant in the tubes. 25 and the header IS. The surface of the evaporator 13 is adequate for cooling the air in the refrigerator cabinet H, and the contents of freezing trays or the like placed on the surface thereof at 13a.

While I have shown my invention embodied in a particular evaporator for a household refrigerating machine, other modifications will occur to those skilled in the art. I do not, therefore, desire my invention to be limited to the particular construction shown and described, and I intend in the appended claims to cover all modifications within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A flooded evaporator for refrigerating machines comprising a header and means providing two groups of refrigerant circulating passages for containing refrigerant, all of the passages in one of said groups communicating with said header, means injecting liquid refrigerant into a plurality of the passages of said one of said groups of passages for producing a circulation of refrigerant in said one group of passages, means providing communication between said header and the other of said groups of passages for removing liquid and gaseous refrigerant from said header and injecting said removed refrigerant into-a plurality of the passages in said other group of passages for producing a circulation of refrigerant in the second of said groups of passages, and means for withdrawing gaseous refrigerant from said second group of passages.

2. A flooded evaporator-for refrigerating machines comprising two headers and means providing two groups of depending refrigerant circulating passages for containing refrigerant, one of said groups of passages communicating with one of said headers, the other of said groups of passages communicating with the other of said headers, means injecting liquid refrigerant into a plurality of the passages of said one of said groups of passages for producing a circulation of refrigerant in said one group of passages, means providing communication between said one header and said other group of passages for removing liquid and gaseous refrigerant from said one header andinjecting said removed refrigerant into a plurality of the passages in said other group of passages for producing a circulation of refrigerant in said other group of passages, and means for withdrawing gaseous refrigerant from said other header.

3. A flooded evaporator for refrigerating machines comprising two headers and means providing two groups of depending refrigerant circulating passages for containing refrigerant, one of said groups of passages communicating with one of said headers and the other of said groups of passages communicating with the other of said headers, means injecting liquid refrigerant into each passage of said one group of passages for supplying refrigerant to said evaporator and for producing a circulation of refrigerant in said one group of passages, means providing communication between said one header and said other group of passages for removing liquid and gaseous refrigerant from said one header and for producing a circulation of refrigerant in said other group of passages, and means for withdrawing gaseous refrigerant from said other header.

4. A flooded evaporator for refrigerating machines comprising two headers and means providing two groups of depending refrigerant circulating passages for containing refrigerant, one of said groups of passages communicating with one of said headers and the other of said groups of passages communicating with the other of said headers, means including a manifold and a plurality of ducts communicating therewith for supplying liquid refrigerant to said one group of passages and for producing a circulation of refrigerant in said one group of passages, means including a second manifold and a plurality of ducts providing communication between said one header and said other group of passages for removing liquid and gaseous refrigerant from said one header and for producing a circulation of liquid refrigerant in said other group of passages, and means for withdrawing gaseous refrigerant from said other header.

. 5. A flooded evaporator for refrigerating machines comprising two headers and means providing two groups of U-shaped depending refrigerant circulating passages for containing refrigerant, one of said groups of passages communicating with. one of said headers and the other of said groups of passages communicating with the other of said headers, means injectingliquid refrigerant into a plurality of the passages of said one group of passages for producing a circulation of refrigerant in said one group of passages, means providing communication between said one header and said other group of passages for removing liquid and gaseous refrigerant from said one header and injecting said removed refrigerant into a plurality of the passages in said other group of passages for producing a circulation of refrigerant in said other group of passages, and means for withdrawing gaseous refrigerant from said other header.

6. A flooded evaporator for refrigerating machines comprising two headers and means providing two groups of U-shaped depending refrigerant circulating passages for containing refrigerant, one of said groups of passages communicating with one of said headers and the other of said groups of passages communicating with the other of said headers, means including a manifold and a plurality of ducts connecting said manifold and said one group of passages for supplying liquid refrigerant to said one group of passages and for producing a circulation of refrigerant in said one group of passages, means including a second manifold and a plurality of ducts providing communication between said one header and said other group of passages for removing liquid and gaseous refrigerant from said one header and for producing a circulation of refrigerant in said other group of passages, and

means for withdrawing gaseous refrigerant from said other header.

7. A flooded evaporator for refrigerating machines comprising two metal sheets secured together and having indentations formed therein providing two headers and two groups of depending refrigerant circulating passages, one of said groups of passages communicating with one of said headers, the other of said groups of passages communicating with the other of said headers, means injecting liquid refrigerant into a plurality of the passages of said one group of passages for producing a circulation of refrigerant in said one group of passages, means providing communication between said one header and said other group of passages for removing liquid and gaseous refrigerant from said one header and injecting said removed refrigerant into a plurality of the passages in said other group of passages for producing a circulation of refrigerant in said other group of passages, and means for withdrawing gaseous refrigerant from said other header.

8. A flooded evaporator for refrigerating machines comprising two metal sheets secured together and having indentations formed therein providing two headers and two groups of depending refrigerant circulating passages, one of said groups of passages communicating with one of said headers and the other of said groups of passages communicating with the other of said headers, means including a manifold and injecting liq-- uid refrigerant into a plurality of the passages of said one group of passages for producing a circulation of refrigerant in said one group of passages, means including a second manifold pro viding communication between said one header and said other group of passages for removing liquid and gaseous refrigerant from said one header and injecting said removed refrigerant into a plurality of the passages of said other group of passages for producing acirculation of refrigerant in said other group of passages, and means for withdrawing gaseous refrigerant from said other header.

9. A flooded evaporator for refrigerating machines comprising two metal sheets secured together and having indentations formed therein providing two headers and two groups of depending refrigerant circulating passages, one of said groups of passages communicating with one of said headers, the other of said groups of passages communicating with the other of said headers,

means including a manifold and ducts connectfrom said other header.

LEONARD W. ATCHISON. 

